Unit 4: Signal Transduction Pathways (STP)

Question 1

What are the three components of a STP?

Answer 1

Reception - signaling molecule/ligand is recognized by receptor protein
Transduction - Signal cascades relay signal from receptor to targets; often amplifying signal
Response - target response

Question 2

What is the structure of a receptor protein?

Answer 2

An external ligand-binding domain (recognizes specific chemicals like peptides or protein)
A hydrophobic membrane-spanning region
An intercellular domain

Question 3

Kinase __ proteins

Phosphates __ proteins

Answer 3

Activates

Deactivates: to not waste energy

Question 4

Not all ___ and shape determines function.

Once occurred, the intracellular domain changes shape initiating transduction

Answer 4

Ligands can bind
Some are water soluble and must bind to receptors on the outside of the cell.
Some are ligand soluble and must bind to receptors inside the cell.

Question 5

Another way to activate is a ___

Answer 5

Secondary messenger/cAMP

It synthesizes molecules, then those go around and activate others.

Question 6

What are the two types of responses?

Answer 6

Nuclear and cytoplasmic

Question 7

What are nuclear responses?

Answer 7

Signaling pathways regulate protein synthesis

Question 8

What are cytoplasmic responses?

Answer 8

Signaling pathways regulate protein activity. It activates by cutting/cleaving parts of that inhibit regions/keep cells dormant; changes the shape.

Question 9

What is an example of receptor proteins in eukaryotes?

Answer 9

G-protein coupled receptors

Question 10

Why is it beneficial to turn off proteins?

Answer 10

To have them produce in the background. When you need them, you have a stock of them giving you a quick response.